284 



NEBRASKA STATE HORTICULTURAL SOCIETY. 



In five of the orchards the average yield per tree was greater from 

 sprayed trees than from unsprayed ones, while in one orchard the re- 

 verse was true. The percentages of increased yield of sprayed over 

 unsprayed trees varied from 6 to 104. The differences in these percent- 

 ages were due probably very largely to differences in the prevalence 

 of scab in the different localities. In the three orchards where scab 

 did comparatively little damage even to unsprayed trees, namely, the 

 orchards at Falls City, Glen Rock, and Nebraska City, the average 

 increase in yield due to spraying v.-as only 16 per cent. In the case, 

 however, of the other three orchards, Lincoln, Tecumseh, and Pawnee 

 City, where injury from scab was much more pronounced the average 



■ix-' 



Fig. 5. Large sprayed tree of Mis- 

 souri Pippin apple in tlie Tecumseh 

 orchard with its entire crop of fruit. 

 Sound fruit (JVz bushels) on the right, 

 scabby and wormy fruit (5 bushels) 

 on the left. 



V-L 'Mf^ ^&!aa- 



Fig. 6. Large unsprayed tree of 

 Missouri Pippin in the Tecumseh or- 

 chard with its entire crop of fruit. 

 Sound fruit (2 bushels) on the right, 

 and scabby and wormy fruit (6 bush- 

 els) on the left. 



gain in yield from spraying was 72 per cent (see figures 5, 6, and 7). 

 Scab decreases the yield not only by attacking the flowers and very 

 small fruits, causing them to drop, but also by checking the growth of 

 the fruit that hangs on. In the Lincoln orchard, where scab was 

 abundant, records made from 70 bushels of Ben Davis and Winesap 

 apples show the individual fruits from sprayed trees to have averaged 

 about nine per cent larger than the fruits from unsprayed trees. The 

 fruits that were free from scab on a single tree of Winesap, a variety 

 very susceptible to scab, averaged 19 per cent larger than the scabby 

 fruits on the same tree. 



The average yield for the six orchards was 8.4 bushels per tree from 



